Manufacture of electrodes



Patented July 19, 19 38 v l 1 11 1 ".zazazsi f Q f f n 4 ML-Ma'NUFAoTURE on memories" synai'an ata nnph, tint Pleasant; wanaa' i p I worth,.London, England, as'signor' to The Aluminum Plant and Vessel Company. Limited, 7 Point Pleasantrwandsworth,London; -England ApplicationfFelii-uary s, 1936, sem no; 52,711 bgrnoreai Britain February 6, 1935 e e e e 1 Claim, (error-)? l I; This invention relate slj to the manufacture of out its length, thereby ensuringthat, the current YeIectmdesand has particular 'reference to the 1 .manuiacture oi, electrodes which are composed ofrelatively. expensive or valuable 'metals ffor instance; nickel and which are required to' carry heavy electric currents." H A 1 Such electrodesare used in connection with the electrolysis of liquids, as, for example, in the production of metallicsodium from caustic soda to provide an improved and simplified method t of forming such electrodes and an improved form of electrode which is less expensive and which at the same time possesses the conductivity and the electrode is substantially-constant throughdensity shall remain substantially constant not I withstanding Ithe fact" that \liquid circulating "openings are thu'sprovided; In ordertoprovide a good electrical connection between thetwo'elements, oithe electrodfthe ring-like element or elements oi copperor other relatively'inexpensive metal is preferably cast,weldedorsilver-soldered in position 'on theupper end of the flared part M and th y. a e usua y f r d y st Such of the body' portion of the electrode. .In this I i i g castings are relatively'expensive to machine all connection it has been found that owing to the H Over, the m c q enlyflddihg t0 the costs searching or penetrating nature of certain elec- 1 n but being ge ra y n es ry o the Pu p e Of trolytes, e. g. hot caustic soda, and distortions obta n ng an even thi k n f r n r n arising in the use of theelectrode, mechanical fi that the surface ofthe electrode shall be parallel means, such as riveting jor bolting, of" the, two i l jgwith its neighbouring electrode. Furthermore, parts of the electrode are unsuitable as it has i I] t 118$ been found diffielllt t0 ensure tS c vbeen found that the electrical contact becomes I j castings are free from blowholes, porous places progressively worsej j under operating conditions and'oxide inclusions and experience has shown wing tothe gradual seepage'of the electrolyte at c as Often breakdown p y between such mechanically united surfaces, par-- 2 h use Owing to uc t Inthis Connection hticularly in instances where spray is carried above ,it must be borne in mind thatsuch porous places th surface f the electrolyte. i i 4 or blow holes left in the machined casting give In order that the said invention may be clearly rise to process troubles due to the reduced effecunderstood and readily carried into eflect the, 2 tive currenta ryi g pa ty f the p t same will now, be more fully described with ref P Of the Section at which t 6 and thus erence to the accompanyingdrawing, in which:-,- the eflective current density from one electrode Figs .1 a z' respectively in vertical to another is less thaninsuchp aces Where the tional elevation and in plan an electrode prometal free from Such defectsduced in accordance with the present invention. 0 The m Object v the present invention is The electrode shown in the accompanying 0.

drawing is made up of a hollow cylindrical body portion a composed of the relatively expensive metal such as nickel and a-surmounting ringlike element b composed of the less expensive results in the formation of the desired liquid cir other attributes necessary for enabling the same electrically conducting metal such as copper. to be used for electrolysis and, similar purposes. its upper end the body -t is provided with A0601 ding to inventlonthe Improved r a series of circumferentially spaced slits, slots of electrode is composed of two parts, to'wit,v a or openings 0 t pe t th liquid under t t. U i hollow cylindr cal b y D Q ed 05 a ment to pass therethrough and'is flared outward-. r

relatively pensive metalfs e e; nickel, n ly in, the manner shown, the effective current surmounting ring-likeelement united as for carrying cross sectional area of the electrode reexample; by u n. Weldme i el wlth h maining substantially constant throughout its P end P the body poljtlon n composed 0i a length. The hollow cylindrical body portion may less expenswe good 'electncallyconductingmetal be out from a metal tube but for economical'rea such as copper the cylindrical body portion sons it is preferably formed from a fiat sheet of ing preferably formedofsheet metal having suitmetal] which is rolled or curved so that its oppo able liquidnoirculating openings formed therein. it ed 1 b ht t Y m d it b1 ,1 In carrying the invention into effect according 5 e 885 mug oge er a y to one convenient mode, the hollow cylinder of joined P for example by welding the welding sheet metal is formed at its upper end'withia, extendmg only to the lower e of that Portion 50, series of circumferentially spaced slits, slots or" of the body which 18 Subsequently fl d-- Y openings and the'slitted, slotted or apertured end p v d the upp r par 0 t y in r r fiat isfiared outwardly in such a manner that the sheet with a series of slits or slots. e Subseeffective current-carrying cross-sectional area of quent flaring oi the upper end of the'cylinder 55 55 culating openings, without loss of cross sectional conducting area.

The surmounting ring-like element of copper or the like is cast, welded or silver-soldered in positionon the upper end of the flared part of the body portion of the electrode or on the tongues between which the aforesaid openings are formed. If desired, the area of contact and,

the anchorage between the two elements may be increased or improved by providing the tongues with a series of pins or other protuberances which are embedded in the ring-like. element or elements.

From the foregoing it will be appreciated that the two-part, two-metal electrode produced in accordance with the present invention possesses many advantages over the one-piece cast nickel electrodes used hitherto. In the first place, it is free from the drawbacks inherent with any form of casting when used for electrolytic and like purposes and, secondly, the costs can be materially reducedsince not only does the invention enable sheet metal to be utilized for the formation of the electrode, thus saving machining and scrap, but, owing to the use of a copper or like surmountingring, the mass of the more expensive material, for instance, nickel, used'is considerably of nickel.

A bi-metallic electrode for use in the electrolysis of' caustic alkalis, consisting of a liquid immersion part in the form of a hollow cylindrical body portion composed of nickel and a surmounting ring-like part composed of copper, the upper end of the nickel body portion being flared outwardly and of constant cross-sectional area and 'current'carrying capacity, said upper end being formed with a series or liquid circulation openings constituted by circumierentially spaced slits which, by the flaring, have theform oi slots, and the ring-like part'oi copper being united'by fusion with the upper end of the outwardly flared part 25 SYDNEY JAMIESON RALPH. 

